“Juno” offers pictures of the moon Europa
Jupiter’s moon Europa has an icy surface. NASA’s “Juno” research probe has now flown past the bizarre celestial body, capturing images at a resolution never before achieved. What the researchers hope from these images.
dhe Jupiter satellite Europa is the sixth largest moon in our solar system and has captured the imagination of astrophysicists for years. Huge fountains of water vapor and fine ice particles shoot from the surface of this celestial body some 200 kilometers into space.
That in itself is spectacular, but the most exciting thing is that there must be a vast ocean of liquid water beneath the Europa ice sheet. And because water is an important prerequisite for life, the researchers speculate that life forms could exist in the interior of Europe.
But with a moon far from the sun, the surface of which is even covered with icy ice, how can there be water under this liquid? The scientists have an answer to that: the powerful gravity of the giant planet Jupiter is causing strong tidal friction in the interior of Europe. This releases heat, which can be sufficient to raise the temperature above the freezing point of water.
Flyby in 352 kilometers
The first pictures of Europa’s fountains were taken in 2013 by the Hubble Space Telescope. Now, NASA’s “Juno” research probe has flown past Jupiter’s moon Europa at a distance of just 352 kilometers. The probe’s first photo has landed on Earth and has been published by NASA. It shows the icy crust of the moon in an area called Annwn on the equator. The pixels of the image recorded with the so-called “JunoCam” are one kilometer in size.
The research probe only had a two-hour window to take pictures of the surface of Europa as it flew past the moon at about 15 miles per second. But everything seems to work as intended.
“It’s too early to draw a definitive conclusion, but all indications are that Juno’s flyby of Europe has been a great success,” said Scott Bolton of the Southwest Research Institute in San Antonio. “This photo is just a harbinger of the new insights about Europe that Juno will bring us with its instruments and sensors.”
Comparison with images from “Voyager 2”
The probe has obtained not only optical data on the structure of Europa’s ice surface, but also on the composition and ionosphere of the moon, which interacts with Jupiter’s magnetic field. “We’ll compare Juno’s images with previous images of Europe and see if anything on the surface has changed over the past two decades,” said Juno researcher Candy Hansen of the Planetary Science Institute in Tucson, Arizona.
In the past, the “Voyager 2” and “Galileo” research probes had images of the surface of Europa – albeit at a lower resolution. Thanks to Juno, researchers now have a much higher resolution surface map of the moon.
Overall, the new information about Europa’s geology is an important basis for the “Clipper” mission, which NASA plans for 2024. This research probe will use a special radar to look through the ice surface of Europa and possibly detect liquid water underneath.
With instruments sensitive to magnetic fields and gravity, the sub-glacial water resources could be measured more accurately. It will also measure the composition of Europe’s thin atmosphere.
If there were life forms in the European water world, then telltale molecules could enter the moon’s atmosphere with the fountains. If “Clipper” can prove this, it would be spectacular. Well, it won’t be really exciting in a few years. But today Juno is an important factor for future exploration of Europa, the moon that could harbor life.
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